Defrosting apparatus



DEFRO S T I NG APPARATUS.

Filed Nov. 25, 1931 I Patented June 6, 1933 UNITED STATES PAUL RAYMOND, F FAIBHONTQWEST VIRGINIA DEFBOSTING APPARATUS Application tiled November 25, 1931. Serial No. 577,334.

This invention relates to mechanical refrigeration and refrigerators and has for its primary obect to provide both household and commercial refrigerators of the compressor-condenser-expander type with simplified means b which they w1ll be au tomatically de rosted at predetermined periods.

One of the greatest, if not the` greatest 0 expense in the kservicing of mechanical refrigerators is due to the fact that the owners or operators fail to defrost at reasonable intervals and hence allow a very substantial coating of ice'to form on the refrigerating coils. This coating or layer of ice not only acts as an insulator and causes a much greater use of power to maintain the refrigerating compartment at the desired temperature, but the continually increasing thickness of the 2 layer causes the partitions to be forced out of shape, disrupts pipe joints and gives rise to many other troubles which require the services of skilledl mechanics.

`The present invention is designed to render a mechanical refrigerator entirelyT foolproof, and the defrosting mechanism disclosed herein is designed to secure the complete defrosting of the coils at each operation, and the defrosting operations are 0 caused toy automatically occur at predetermined intervals so that the human element is entirely eliminated. Moreover, the defrosting mechanism is so designed that the slight cost of operation is exceeded many times by the saving in power consumption due to the absence of insulation on the refrigerator coils.

Other objects and advantages of the invention will be in part apparent and in part pointed out in the following detailed description taken in connection with the accompanying drawing, in which,

Figure 1 is a more or less diagrammatic view of a conventional mechanical refrigerator of the flooded type, showing my novel defrosting mechanism incorporated therein, and

Figure 2 is a vertical sectional view, on an enlarged scale, of the reversing valve and its 0 operating mechanism, for permitting a tempo'iiary flow of hot gases to the refrigerating co1 Referring to the drawing in more detail, the numeral 1 indicates a refrigerating cabinet of the usual type, including a horizontal partition 2 which divides the cabinet into a lower compartment 3 for receivin the operating mechanism and an upper re rigerating compartment 4.

Mounted within the lower compartment 3 l are the motor 5, compressor 6, condenser 7 and receiver 8. Within the refrigerating compartment 4 is a float-controlled expander 9 including refrigerating coils 10.

A conduit 11 is adapted to convey refrigeris ant from the receiver 8 to the expander 9 and a conduit 12 serves to return the expanded gases to the compressor 6. The compressed gases are carried from the compressor 6 to the condenser 7 by a conduit 13 which com- '70 municates with an extension 14 of the condenser pipe coil. Connected with the pipe extension 14 is a conduit 15 which leads to the interior of the expansion chamber 9.

A valve 16 is located at the juncture of the 'Il pipe extension 14 and conduit 15, and serves to normally cut ofi1 communication between the high pressure side of the system and the conduit 15. This valve is shown on an enlarged scale in Figure 2 and comprises a -sn plunger 17 carrying a needle valve element 18 which normally rests on valve seat 19. Cooperating with the plunger 17 is a solenoid 20. It will be understood that when the solenoid is energized the plunger will be lifted and the valve consequently opened. Connected in the circuit 21 of the solenoid 20 is a clock 22 provided with a switch (not shown) adapted to be periodically closed and thereby energize the windings of the V solenoid.

Also connected in the electrical circuit 21 is a heating coil 23 which surrounds a portion of the conduit 15. This coil it will be understood is energized each time the circuit is closed through the solenoid and serves to heat the gases passing through the conduit 15 to the expander 9.

A conventional connector plug 24 is associated with the circuit 2l and it will of course 100 21 is then again o into the expander will, of course, raise its' temperature and cause any ice formed thereon and on the coils 10 to melt. The circuit ned and the valve 18 allowed to close. t each operation of the time-controlled mechanism the electrical heating coil 23 is also energized and thus heats the gases passing through the conduit 15 prior to their entrance into the expander 9. Of course if the compressor has not been shut down too long prior to the opening of the valve 16 the gases will be fairly hot, but if the compressor has been shut down for ah 25 considerable period of time prior to the 0peration of the time-controlled mechanism the gases on the high-pressure side of the system will not be sufficiently hot to quickly defrost the refrigerating coils and it is for this reason that the electrical heating coil 23 is provided so as to impart the desired heat energy t0 the gases under such circumstances.

From the lforegoing `description taken in connection with the accompanying drawing it will be apparent to those 'skilled in the art f that I have provided an extremely simple and inexpensive construction by means of which hot gases are conveyed to the expander of a refrigerating system at predetermined intervals; that the mechanism is entirely automatic in its operation and that in the event` the gases are not sufficiently hot to perform the defrosting operation in the prescribed time interval the electrical heating coil will impart the necessary heat energy to such gases prior to their entrance into the expander.

presser-condenser-eva orator type, a conduit leading from the r.hig pressure side of the system to the evaporator, a valve normally c osing said conduit, means for periodically opening and closi said valve, and means foi` heating the con uit.

3. In a mechanical refrigerator of the comressor-condenser-evaporator type, a conduit eading from thehigh pressure side of the s stem to the evaporator, a valve normall c osing said conduit, anelectric heating coel encirc ing-a ortionfof said conduit, and timecoritrolled e ectrical means for periodically opening said valve and energizing said heatmg co1 4. In a mechanical refrigerator of the compressor-condenser-evaporator type, a conduit leading from the high pressure side of the system to the evaporator, a valve normally closing said conduit, a solenoid for operating said valve, an electric heating coil encircling a portion of said conduit, an electric circuit in whichsaid solenoid and heating coil are connected, and a time-controlled switch for periodlcally closing said circuit.

PAUL- HAYMON D.

. In accordance with the patent statutes I 'l have described what I now believe to be the referred form of construction, but it will ge apparent that various minor changes may be made in the details of construction without departing from the spirit of the invention and all 'such changes are intended to be in- 55 eluded within the scope of the appended claims.

What I claim is: i

1. In a mechanical refrigerator of the compressor-condenser-evaporator type, a conduit 50 leading from the high pressure side of the system to the evaporator, a valve normally closing said conduit, a solenoid for opening said valve, and a time-controlled switch for periodically energizing said solenoid.

2. In a mechanical refrigerator of the com- 

